Atlas of the Four-Bar Linkage: Using Geometry Expressions to Investigate the Infinite

For many years, the coupler-curve atlas by Hrones and Nelson has been a valuable aid for designing four-bar linkages. Today, computers can quickly and accurately analyze displacement, velocity, and acceleration of the coupler point which traces the curve. However, even in the age of computers, an atlas is unsurpassed as a way to see relationships among these curves and choose the best for a particular design by thumbing through paper copies rather than looking at them individually or even in small groups on a computer screen.

This atlas of four-bar linkage coupler-curves facilitates quick visual comparisons. The atlas aids conceptual design by allowing easy perusal of a large number of curves produced by the following linkage categories: Crank Rocker, Double Crank, Crank Slider and Inverted Crank Slider. When an acceptable design is found, the curve can be analyzed and the linkage parameters varied to improve performance by using the appropriate computer software.